Thanks for all the replies...sounds like I'll have no problems switching it out if I have to so long as I get the right brackets for the accessory equipment - I'd just as soon keep the 454 but not knowing its history, I'm just making sure I have a relatively easy option.

Ive been told 2 different things about the tranny and motor mounts - do the ones for the 454 line up and work for a 350? Seems from this thread that they do.

I should probably just go buy the thing and if the 454 gives up the ghost - I'll pull it, rebuild it, and pop in in something a littl emore fun